Some of the basic approaches to storm protection involve covering and protecting openings and windows in structures to prevent damage from high winds, rain and flying debris. The wind borne debris acts as a missile when it hits windows, doors and other openings, piercing the structure and compromising the building's structural integrity. In extreme winds of a hurricane, cyclone or tornado, a breached opening in a structure can allow damaging wind and rain to enter the building and put extreme design strains on the roof. The roof can detach from the house or have severe damage that would not have otherwise occurred if openings were protected effectively.
As a result of the danger and destruction caused by storms in certain parts of the United States, a number of State and local governments have enacted rules and regulations to prevent or minimize damage. The State of Florida, for example, has enacted regulations and building codes due to the frequent occurrence of hurricanes in a number of counties in Florida, such as Brevard, Dade and Broward counties.
One approach to providing protection, which is considered the most cost-effective is the use of plywood, which is firmly attached to the building by nails or screws. Plywood sheets are heavy, weighing approximately 50 pounds each. The plywood must be cut to fit the window or door. The plywood is normally drilled and screwed into the building thus defacing the structure, requiring craftsmanship, labor and hardware. So, what seems to be cost-effective becomes expensive, time-consuming and potentially dangerous if all openings are covered, such that occupants are trapped inside in an emergency. It also makes the interior of a structure very dark, if a power outage occurs. The use of plywood also requires attachment from the outside, again a dangerous activity if a storm is approaching and ladders are required to reach higher floors of a structure.
Another approach is the use of lamination systems or films having a thickness of approximately 10 to 20 mils that are applied to the interior of glass panes to prevent shattered glass from collapsing into the structure. However, since the film is on the inside of the glass, it cannot absorb enough energy from the glass fast enough to prevent a failure or fracture of the glass if the glass pane is struck by debris or projectiles. So, the use of laminated films or tape will reduce rain damage and the risk of individuals being cut by flying glass; but economic loss and damage are not avoided by this method if glass panes are fractured.
Other methods for protecting the windows or doors of a building include products marketed as hurricane or storm shutters. There are basically four kinds available on the market; the storm panel, accordion shutters, colonial/Bahama shutters, and roll-up shutters. Neither of the existing shutter types is without need for improvement.
Storm panels are fabricated from galvanized, aluminum steel or corrugated steel panels as described in U.S. Pat. No. 6,189,264 to DiVeroli and are applied to the exterior of the building in a manner that is similar to the attachment of plywood. DiVeroli describes a means for opening and closing the rigid panels on a track; the operation can be from inside the structure.
Accordion shutters are generally made from extruded aluminum, which form an accordion shape when opening and closing. The accordion shutters are usually permanently attached to the structure, so the aesthetic appearance may often be at odds with the structural design of the building; for example, completely in discord with historic or gothic architecture. An example of an accordion shutter is in U.S. Pat. No. 5,957,185 to Robinson, et al.
The colonial/Bahama shutters shown in U.S. Pat. No. 6,886,294 to Carey can be made of wood, metal or a synthetic material that is permanently attached to a building and incorporated into an exterior window. This shutter has a style that is suitable for a limited kind of architecture and is known to block or detract from the view through a structural opening. Carey provides a rectangular frame designed and constructed to improve the structural integrity of colonial/Bahama shutters.
The roll-up type of hurricane shutter is disclosed in U.S. Pat. No. 4,723,588 to Rüppel. FIG. 1 is an illustration of a conventional roll-up shutter that has several connected metal panels 30 that can be rolled up into a housing or cover 20 with a service cover 10. The shutter is attached permanently to the exterior of a structure and can be motorized for ease of use and operation from the interior of the building.
FIG. 1A shows a split curtain style roll up shutter 110 for double windows. The split curtain style uses a ball bearing assembly at a center point 115 and another ball bearing assembly (not shown) at the end of the idler shaft on side wall 120.
The roll-up shutter overcomes many objections to other protective means described above with ease of use, permanent installation so there is no rush to install before the storm hits, a not-too-objectionable housing attached to a building's facade, and the ability to operate the opening and closing from inside the structure. The major problem with the roll-up shutter is the requirement for periodic maintenance to ensure operation.
In FIG. 2, the service cover 10 is removed from the housing 20 to reveal the major requirement for maintenance, the ball bearing assembly 40 attached to idler shaft 45. The existing bearing assemblies in roll-up shutters have a serviceable life of a few years, approximately 3 to 5 years. It appears that the bearing assemblies are not intended for storm shutters and certainly not intended for use in corrosive environments near oceans that spawn hurricanes or cyclones. Periodically, the bearings have to be replaced because the plastic elements disintegrate, become brittle, break or crack; the rainwater and sea spray get into the bearing assembly causing the ball bearings to rust and corrode. The failures of ball bearing assemblies lead to inoperable shutters with idler shafts that jam or stick. This leads to service calls, replacement of bearing assemblies, labor and expense. Imagine the nightmare of hurricanes coming and a multi-story condominium building with roll-up storm shutters on hundreds of windows with jammed or broken ball bearing assemblies in some or all of the shutters.
Thus, a need exists for roll-up storm or hurricane shutters that have a ball bearing assembly that does not jam, does not rust, does not corrode, does not stick, does not need to be replaced or serviced on a frequent basis, in time for, or during the hurricane season. It would fill a significant commercial need to have a ball bearing assembly with a serviceable life span of more than 10 years. The present invention provides such an assembly.